PostgreSQL Source Code: src/include/common/fe_memutils.h Source File

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fe_memutils.h
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1/*
2 * fe_memutils.h
3 * memory management support for frontend code
4 *
5 * Copyright (c) 2003-2025, PostgreSQL Global Development Group
6 *
7 * src/include/common/fe_memutils.h
8 */
9#ifndef FE_MEMUTILS_H
10#define FE_MEMUTILS_H
11
12/*
13 * Assumed maximum size for allocation requests.
14 *
15 * We don't enforce this, so the actual maximum is the platform's SIZE_MAX.
16 * But it's useful to have it defined in frontend builds, so that common
17 * code can check for oversized requests without having frontend-vs-backend
18 * differences. Also, some code relies on MaxAllocSize being no more than
19 * INT_MAX/2, so rather than setting this to SIZE_MAX, make it the same as
20 * the backend's value.
21 */
22 #define MaxAllocSize ((Size) 0x3fffffff) /* 1 gigabyte - 1 */
23
24/*
25 * Flags for pg_malloc_extended and palloc_extended, deliberately named
26 * the same as the backend flags.
27 */
28 #define MCXT_ALLOC_HUGE 0x01 /* allow huge allocation (> 1 GB) not
29 * actually used for frontends */
30 #define MCXT_ALLOC_NO_OOM 0x02 /* no failure if out-of-memory */
31#define MCXT_ALLOC_ZERO 0x04 /* zero allocated memory */
32
33/*
34 * "Safe" memory allocation functions --- these exit(1) on failure
35 * (except pg_malloc_extended with MCXT_ALLOC_NO_OOM)
36 */
37extern char *pg_strdup(const char *in);
38extern void *pg_malloc(size_t size);
39extern void *pg_malloc0(size_t size);
40extern void *pg_malloc_extended(size_t size, int flags);
41extern void *pg_realloc(void *ptr, size_t size);
42extern void pg_free(void *ptr);
43
44/*
45 * Variants with easier notation and more type safety
46 */
47
48/*
49 * Allocate space for one object of type "type"
50 */
51 #define pg_malloc_object(type) ((type *) pg_malloc(sizeof(type)))
52#define pg_malloc0_object(type) ((type *) pg_malloc0(sizeof(type)))
53
54/*
55 * Allocate space for "count" objects of type "type"
56 */
57 #define pg_malloc_array(type, count) ((type *) pg_malloc(sizeof(type) * (count)))
58#define pg_malloc0_array(type, count) ((type *) pg_malloc0(sizeof(type) * (count)))
59
60/*
61 * Change size of allocation pointed to by "pointer" to have space for "count"
62 * objects of type "type"
63 */
64#define pg_realloc_array(pointer, type, count) ((type *) pg_realloc(pointer, sizeof(type) * (count)))
65
66/* Equivalent functions, deliberately named the same as backend functions */
67extern char *pstrdup(const char *in);
68extern char *pnstrdup(const char *in, Size size);
69extern void *palloc(Size size);
70extern void *palloc0(Size size);
71extern void *palloc_extended(Size size, int flags);
72extern void *repalloc(void *pointer, Size size);
73extern void pfree(void *pointer);
74
75 #define palloc_object(type) ((type *) palloc(sizeof(type)))
76 #define palloc0_object(type) ((type *) palloc0(sizeof(type)))
77 #define palloc_array(type, count) ((type *) palloc(sizeof(type) * (count)))
78 #define palloc0_array(type, count) ((type *) palloc0(sizeof(type) * (count)))
79#define repalloc_array(pointer, type, count) ((type *) repalloc(pointer, sizeof(type) * (count)))
80
81 /* sprintf into a palloc'd buffer --- these are in psprintf.c */
82 extern char *psprintf(const char *fmt,...) pg_attribute_printf(1, 2);
83extern size_t pvsnprintf(char *buf, size_t len, const char *fmt, va_list args) pg_attribute_printf(3, 0);
84
85#endif /* FE_MEMUTILS_H */
#define pg_attribute_printf(f, a)
Definition: c.h:232
size_t Size
Definition: c.h:610
char * pstrdup(const char *in)
Definition: mcxt.c:1759
char * psprintf(const char *fmt,...) pg_attribute_printf(1
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:1610
void pfree(void *pointer)
Definition: mcxt.c:1594
void * palloc0(Size size)
Definition: mcxt.c:1395
void * pg_malloc(size_t size)
Definition: fe_memutils.c:47
void * palloc(Size size)
Definition: mcxt.c:1365
void * palloc_extended(Size size, int flags)
Definition: mcxt.c:1417
void * pg_malloc_extended(size_t size, int flags)
Definition: fe_memutils.c:59
char size_t pvsnprintf(char *buf, size_t len, const char *fmt, va_list args) pg_attribute_printf(3
char * pg_strdup(const char *in)
Definition: fe_memutils.c:85
void * pg_malloc0(size_t size)
Definition: fe_memutils.c:53
void pg_free(void *ptr)
Definition: fe_memutils.c:105
char * pnstrdup(const char *in, Size size)
Definition: mcxt.c:1770
void * pg_realloc(void *ptr, size_t size)
Definition: fe_memutils.c:65
args
const void size_t len
static char * buf
Definition: pg_test_fsync.c:72

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